It is conventional to form candles with a centrally positioned wick around which a fuel, such as wax, is poured and solidifies. The lower end portion of the wick is often attached to a wick support, base or sustainer. Typically, such a wick support is a metal disk with a central hole punched therein into which the lower end of the wick is inserted and the wick support is crimped around the wick. When the wax is poured around the wick, the wick support is embedded in the solidified wax.
A distinct disadvantage of such wicks and wick supports is commonly referred to as “flare-up” or “flash-over”. This phenomenon occurs when the candle burns down to the wick support and molten wax is drawn upwardly through the central bore of the wick support and there is a flare-up or flash-over.
Several attempts have been proposed to solve this problem. One such attempt is disclosed in U.S. Pat. No. 3,797,990, issued to Avon Products on Mar. 19, 1974. This patent discloses the use of a safety wax, which is non-flammable at the temperature generated as the candle burns, below or on top of the wick support. In one embodiment, this patent discloses that a polyamide may be used instead of the safety wax. While such safety wax will generally prevent flare-up or flash-over, it is usable only in container-type candles and not self-supporting type candles and is difficult and expensive to manufacture.
Another such attempt is disclosed in U.S. Pat. No. 6,062,847, in which a metal or ceramic wick support in a container candle is at least one-half to one inch above the lowest level of the fuel or wax to prevent flash-over. Also, the bore through the wick support is closed by adhesive or the like.
While somewhat successful in preventing flash-over or flare-up, the attempts as described above are generally limited to container candles and rely solely upon fuel deprivation for extinguishing the flame. Also, such attempts require special containers or additional elements which increase the cost of the candles.
A further prior attempt to eliminate “flare-up” or “flash-over” is illustrated by the prior candle construction shown in FIGS. 5 and 6 of the present application. In this construction, a circular metal base plate 14 is joined to the end of the candle wick 12 by crimping the periphery of an aperture in the plate about the wick. Thereafter, an annular plastic button 15 is threaded onto the wick so as to rest upon the bottom plate, and a melted combustible wax 18 is then molded about the wick to complete the fabrication of the candle. The plastic button 15 was composed of a mixture of a plastic, such as polypropylene, and a flame retardant, such as the brominated, hydrogenated flame retardant sold by PolyOne Distribution Company of Statesville, N.C. under the product designation PP Conc 36 Nat S. Thus in use, when the flame burns down to the area of the button, the flame retardant is released by the heat of the flame, and the flame is extinguished.
While the candle as shown in FIGS. 5 and 6, and as described above, represents a significant improvement, it is not entirely satisfactory since the assembly of the button onto the wick is a time consuming operation which is usually conducted by hand, and the loose fitting of the button on the wick can result in mis-alignment of the button during the molding of the wax to embed the wick. Thus, further improvement is desirable.